Which preposition to use with perfectability

of Occurrences 3%

" "The good time of which you speak," said the Doctor, "when there shall be no more infirmity of age, no growing old, save in years; when there shall be no wasting by disease, through the perfectability of the curative science, or the discovery of some recuperative agency, stronger than the law of decay, will never come.

in Occurrences 2%

But remember, that though these results are brought about by the advance in the mechanic arts, yet that advance is based upon a deeper philosophy, a profounder wisdom, than mere perfectability in those arts.

Which preposition to use with  perfectability